Grinding disk



p 1953 D. M. SUTHERLAND GRINDING DISK 3 Sheets-Sheet 1 Filed Nov. 5, 1952 llllllllllllllllllllllll i INVENTOR. fla/z/wMmwmSzoZ/w/"Mlzag ATTORNEYS.

Sept. 15, 1953 Filed Nov. 5, 1952 D. SUTHERLAND 2,651,976

GRINDING DISK 3 Sheets-Sheet 2 INVENTOR. flaizzwimmswz/Sumermizd,

BY 6 m 26 204 ATTORNEYS.

Patented Sept. 15, 1953 GRINDING DISK Daniel Manson Sutherland, Morrisville, Pa., as-

signor to Lionel M. Sutherland and Douglas G. Sutherland, as trustees Application November 5, 1952, Serial No. 318,818

14 Claims.

This invention relates to grinding disks. More particularly, it has reference to grinding disks of a channeled and grooved type for use in pairs in attrition mills, such as disclosed in U. S. Patent 2,035,994 granted to me on March 23, 1926, and adapted, for example, in the reduction of wood pulp to the fineness required for the manufacture of paper or cardboard therefrom.

My present invention is directed in the main toward predetermining, through an improved arrangement of the channeling and grooving in the opposing surfaces of, the disks, more even distribution and control in the flow of the pulp between them, and more uniformly progressive breaking down of the pulp than possible with grinding disks as heretofore constructed, for the attainment of a more homogeneously treated elivered product of the desired fineness and increased output from the mills.

Other objects and attendant advantages will appear from the following detailed description of the attached drawings wherein:

Fig. 1 is a fragmentary view in section of a pair of opposing grinding disks conveniently embodying my invention shown in the positions which they occupy in the attenuating mill, said section being taken as indicated by the arrows l-I respectively in Figs. 2 and 3.

Fig. 2 is a fragmentary View showing the channeled and grooved grinding face of one of the disks.

Fig. 3 is a View similar to Fig. 2, showing the channeled and grooved grinding face of opposing disk.

Figs. 4 and 5 are enlarged fragmentary views corresponding to Fig. 1 showing in greater detail the construction within the confines of the broken line rectangles 4 and 5 respectively in said Fig. l.

Figs. 6, 7 and 8 are fragmentary views in section taken as indicated respectively by the angled arrows VI-VI, VII-VII and VlZlI--VIII in Fig. 2, and drawn to a much larger scale.

Throughout the drawings, two opposing grinding disks are comprehensively designated [0 and Mia respectively, and in Fig. 1 they are shown in juxtaposition relation as they would be when positioned in attrition mills. It is to be understood that to effect the grinding, one disk may be held stationary while the other is revolved about its axis, or the two may be revolved simultaneously in opposite direction, or they may be rotated in the same direction but at different speeds.

As shown, Figs. 1 and 2, disk I0 is provided with a circular axial opening II and that its grinding face has a relatively wide inner annular area l2, an intermediate annular area [3 of substantially the same width and a comparatively narrow marginal area or check ring Hi at its periphery. As further shown in Fig. 2, two concentric annular channels l5 and I5 separate the areas l2, l3 and I 4. Extending through the innermost annular area [2 is a plurality of relatively wide circumferentially-spaced square bottomed radial channels H, and alternating with these channels are much narrower medially disposed round bottomed radial channels I8 which, together with the channels ll, set apart segmental surface areas it and 20. Disposed crosswise of each segmental area I 9 in parallel relation to the corresponding channel ll is a series of narrow round bottomed grooves 2i, and disposed crosswise of the immediately adjacent segmental area 29 in parallel relation to the radial channel [8 is a series of round bottomed grooves 22 of which the width is less than that of the radial channel i 8. Again referring to Fig. 2, round bottomed radial channels 25 and 26 are also provided in the intervening annular area l3 of the grinding surface of disk l0, these channels being equal in number to the radial channels I! and It in area l2 and in line with them. The radial channels 25 and 26 are all of the same width as the radial channels 18. The segmental portions 21 and 28 set apart by the radial channels 25 and 26 of area I3 and corresponding to the segmental portions l9 and 20 of area 12 are respectively provided with transverse grooves 29 and 30 which are somewhat narrower and of less depth than the grooves 2| and 22 of the area l2, and exceed the latter in number, but extend in the same directions.

The marginal area or check ring M of the grinding face of disk In is provided, in turn, with circumferentially spaced crosswise grooves 3| of which the number is considerably less than the total of the grooves 29 and 30 of the intermediate annular area l3. As shown in Fig. 2, longitudinal axes A of the grooves are tangential to a circle C whereof the diameter is smaller than that of the disk, and from Fig. 8, that they taper in width and decrease in depth outwardly toward the periphery of the disk.

It is to be particularly noted from Figs. 1 and 5 that the depth of the innermost annular channel I5 is equal in depth to that of the cross grooves 2| and 22 of the annular area l0, and that said channel is flat bottomed, that the inner circumferential edge portion 32 thereof is at right angles to the bottom, and that its circumferential outer edge portion 33 is sloped on a bevel. It is also to be noted from Fig. 1 that the depth of the wide radial channels I! increase gradually in depth from that of the grooves 2| and 22 at the innermost annular channel 15 toward the center of the disk. Attention is further directed to the fact that the depth of the outermost annular channel It is equal to that of the crosswise grooves 29 and 30 of the intermediate area 12, and that said channel is flat bottomed like the channel [5, has an inner circumferential edge portion 34 at right angles to the bottom, and an outer circumferential portion 35 which is sloped at a bevel. Another important characteristic to be observed is that the maximum depth of the grooves 3| in the marginal or check ring area I4 corresponds to the depth of the annular channel I 5 with which they directly communicate.

For convenience of machining disk It! may be made in two parts which, as shown in Figs. 1, 2 and 5 are cross hatched in different directions.

Companion disk ma, see Fig. 3, is an exact du plicate of disk It except for the absence of a central opening. Accordingly, in order to obviate the necessity for repetitive description, all corresponding characterizing features of disk Iiia are designated by the reference characters previously employed, however, with addition, in each instance, of the letter a for convenience of more ready distinction.

When the disks l8 and 10a are positioned in the mill with their grinding faces opposed as in Figs. 1, 4 and 5, the grooves of the one will pass the grooves of the other in intersecting angular relation as said disks are differentially rotated, with the result that a grinding and shearing ac tion will take place between them. In the operation of the mill, the pulp is continuously fed under pressure into the central opening H of disk I0 and flows, by way of the radial channels ll, Ila and 18, [8a and cross grooves 2i, Zia and 22, 22a into the annular channel [5, a, then, by way of the radial channels 25, 25a and the cross grooves 29, 29a and 30, 30a, to the annular channels I6, 1611, wherefrom it will be eventually ejected through the cross grooves 3| and am of the check rings I3 and l3a at the peripheries of the disks. By reason of the described arrangement and proportioning of the channels and grooves, the flowing pulp is evenly spread out radially between them and is uniformly discharged at their peripheries after reduction of the fibers, at a rate which is definitely controlled by reason of the variation in the widths of the radial channels and the cross grooves, the cross sectional shaping of the annular channels, and the non-radial disposal and the described shaping of the grooves in the check rings.

Having thus described my invention, I claim:

1. A grinding disk for use in attrition mills having a grinding face with a relatively wide crosswise grooved inner annular area, a cross-,- wise grooved intermediate annular area of substantially the same width, a crosswise grooved narrower marginal check ring area at the periphery, and concentric annular channels separating said areas, the longitudinal axes of the grooves in the marginal or check ring area being tangential to a concentric circle of which the diameter is smaller than the diameter of the disk.

2. A grinding disk according to claim 1, wherein the grooves in the marginal check ring area taper in width and decrease in depth outwardly from the outermost annular channel.

3. A grinding disk according to claim 1, wherein the crosswise grooves of the inner annular :area are all of the same width and depth; wherein the crosswise grooves of the intermediate annular area are likewise all of the same depth but narrower and shallower than those of said inner area and greater innumber; and wherein the maximum depth of the groove in the marginal or check ring area is equal to the depth of the crosswise grooves in said intermediate area.

4. Agrinding disk according to claim 1, wherein the outer of the two annular channels is flat bottomed, the inner circumferential edge portion of said channel is at right angles to the bottom, and the outer edge portion is sloped on a bevel.

5. A grinding disk according to claim 1, wherein the outer of the two annular channels is flat bottomed, the inner circumferential edge por tion of said channel is at right angles to the bottom, and the outer edge portion is sloped on a bevel; and wherein the innermost annular channel is cross sectionally configured like said outermost annular channel.

6. A grinding disk according to claim 1, wherein the crosswise grooves of the intermediate area exceed in number those of the inner area; and wherein the number of crosswise grooves of the marginal or check ring are less than the number of crosswise grooves of said intermediate area.

7. A grinding disk for use in attrition mills having a grinding face with relatively wide inner and intermediate annular areas and a narrower marginal or check ring area at the periphery, concentric annular channels separating said areas, circumferentially spaced radial channels in the inner and intermediate annular areas, crosswise grooves in the segmental face portions of the inner and intermediate areas set apart by the radial channels aforesaid, and circumferentially spaced grooves in the marginal or check ring area with their longitudinal axes tangential to a concentric circle smaller in diameter than the diameter of the disk.

8. A grinding disk according to claim '7, wherein the grooves in the marginal or check ring area taper in width and decrease in depth outwardly from the outermost annular channel.

9. A grinding element according to claim 7, wherein alternate radial channels in the inner annular area are relatively wide, wherein the in tervening radial channels of said area are narrower, and wherein the radial channels in the intervening area are of substantially the same width as the narrow channels in the inner annular area.

10. A grinding disk according to claim 7, wherein the crosswise grooves in the segmental portions of the inner annular area are all of the same width and depth and correspond in depth to that of the innermost annular channel; wherein the crosswise grooves of the intermediate annular area are likewise all of the same depth but narrower and shallower than those of the inner area and correspond in depth to that of the outermost annular channel; and wherein the maximum depth of the grooves in the marginal or check ring area is equal to the depth of the crosswise grooves in the segmental portions of said intermediate area and of said outermost annular channel.

11. A grinding disk according to claim 7, wherein the crosswise grooves in the segmental portions of the inner annular area are all of the same width and depth and correspond in depth to that of the innermost annular channel; wherein the crosswise grooves of the intermediate annular area are likewise all of the same depth but narrower and shallower that those of the inner area and correspond in depth to that of the outermost annular channel; wherein the maximum depth of the grooves in the marginal or check ring area is equal to the depth of the crosswise grooves in the segmental portions of said intermediate area and of said outermost annular channel; and wherein the wide radial channels of the intermediate area increase in depth gradually from that of the crosswise grooves of the segmental portions at the innermost annular channel toward the center of the disk.

12. A grinding disk according to claim 7, wherein the outer of the two annular channels is flat bottomed, the inner circumferential edge portion of said channel is at right angles to the bottom, and the outer edge portion is sloped on a bevel.

13; A grinding disk according to claim '7, wherein the outer of the two annular channels is flat bottomed, the inner circumferential edge portion of said channel is at right angles to the bottom, and the outer edge portion is sloped on a bevel; and wherein the innermost annular channel is cross-sectionally configured like said outermost annular channel.

14. A grinding disk according to claim 7, wherein the crosswise grooves of the intermediate area exceed in number those of the inner area; and wherein the number of crosswise grooves of the marginal or check ring area is less than the number of crosswise grooves of said intermediate area.

DANIEL MANSON SUTHERLAND.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,160,964 Warren Nov. 16, 1915 2,035,994 Sutherland Mar. 31, 1936 2,156,321 Sutherland May 2, 1939 

